Use of implantable cardioverter defibrillators in the New Zealand context from 2000 to 2007.

BACKGROUND

Implantable Cardioverter Defibrillator (ICD) therapy is now standard of care for prevention of sudden cardiac death in high-risk patient groups. In order to determine if the potential benefit of ICD therapy is being realised, ongoing monitoring of ICD therapy is required. This study was conducted to examine ICD therapy in two New Zealand tertiary hospitals.

METHODS

We retrospectively audited patient notes for all patients receiving a first ICD between 2000 and 2007 at two tertiary referral hospitals in New Zealand.

RESULTS

702 patients received their first ICD within the study period, 73% male, mean age 53 years (range 1 to 83), with 73% of devices for secondary prevention. The implant rate increased from 15/million in 2000 to a peak of 44/million in 2004. Antitachycardia pacing was delivered to 21% of patients, appropriate defibrillation to 26% and inappropriate defibrillation to 16% of patients, with frequency of all types of therapy increasing with time since implantation. All cause mortality was 8.6%, and only 7 (1%) died as a consequence of sudden cardiac arrest.

CONCLUSIONS

While increasing across the study period, the ICD implant rate remains low, with a high therapy rate and low mortality rate. This suggests that those receiving ICD therapy are benefiting, but may also imply that the group of patients receiving ICDs is too restricted.